Grid condenser



Jan. 20, 1925.

R. C. PITARD GRID CONDENSER Filed Dec. 15,

mm.. wp.. o m E E -1 /T/VESSES A TTOH/VEVS Patented Jan. 20, 1925.

luNlTlL-:D STATES ROBERT C. PITARD, 0F JACKSON, MISSISSIPPI.

GRID CONDENSER.

Application tiled December 15, 1923. Serial No. 680,941.

To all fio/wm, it may concern:

le it known that I, Romau'r C. lrrann, a citizen of the United Stat cs, and a resident of Jackson, in'thc county of llinds and State of Mississippi, have invented a new and Improved Grid Condenser, of which the following is a full, clear, andexaet description.

The present invention relates to electric condensers of the fixed type, and pertains particularly to a condenser adapted for use 1n the grid circuit of radio receiving tubes.

It is one of the primary objects of the invention to provide a new and improved form of fixed condenser, the attachment of which to arecever is greatly facilitated.

It is a further object of the invention to construct a device of'this character in such a manner that the parts attendant its use are materially reduced.

1t is a 'further object of the invention to employ the elements ot' the tube in such a manner as to form one of the members of the condenser.

With the above and other objects in View, reference is had to the accompanying drawin s, in whichigure 1 isa view partly in elevation and partly in section, ot a condenser construct'.- ed in accordance with the present invention and showing its manner of use:

Fig. 2 is a horizontal sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a view partly in elevation and partly in section of a slightly modified f'orln of the invention;

Fig. t is a detail horizontal view taken on the line 4-4 of Fig. 3. l

Referring more particularly to the drawin s, the reference numeral 5 designates the tu ular member of a tube used in radio apparatus, and 6 designates the tube base. rl`he reference numeral 7 designates a tube socket carried by a socket'v base 8 iu the ordinary manner. t

In Fig. 1, the reference numeral 10 des ignates a metallic band, which is adapted to be clamped around the tube base 6 by means of a bolt 11 and nut 12. l'ntcrposod with respect to this metallic hand, there is a band 13 of dielectric material, such as mica. As shown at 14 in Fig. 1, the lamp socket is grounded with the grid len' or post 15 of the tube, by a conductor bric ged between the metallic section of the tube base (i and the post 15. This forml of the invention operates as follows:

Current is led to the metallic hand l() by means of a suitable, conductor iti, and the energization ol this band l() by an electric current sets up an induced current in the lamp base (i through the medium of the dielectric material 13. '.lhis` induced current is conducted from the tube base by means of the conductor lll to the grid leg l5 of.' the tube and hence to the grid inthe ordinary manner.

This form of the invention when employed, does away with the grid terminal ou the lamp hase and also provides a couvenicnt means for attaching a grid condenser in the grid circuit.

lin that form of the invention shown in Fig. 3, the reference character 2() designates the tube and 21 `the tube hase, and in this emhmlimentot the invention the tube base is enameled or otherwise insulated as indicated by the reference numeral 22. The reference immoral 23 designates the tube socket and such socket is provided with an insulated lining 24 which, together with the insulation 22 of: the tube, serves to insulate thel tube with respect to the tube socket 23. In this form et the invention the tubo socket 23 has a projecting'l portion 25 provided with a. terminal or binding )ost 526, to which is attached a suitable conductor 27. The refer ence numeral 28 designates the grid leg or )ost of the tube, and Said grid leg or post is in electrical connection with. the mctallit| portion of the tube base, by means of a conductor 29.

lin the form of the invention shown in lfig. 3, current is led in by the conductor 27 and the tube socket 23 is energized. [Guen gization of the tube socket induces through the insulation 24 which is in the form of' a. dielectric material, current in the metallic )ortion of the tubo base, and this current is .led by means of the conductor 2t), to the grid post or leg 28, and thence to the grid of thi` tube.

From the lforegoing it is apparent that, the present invention provides a grid condenser of the fixed type in which the method employed in connecting the Igrid condenser in tho grid circuit is greatly simplified over that commonly em iloyed and at present in use, and that, furtlhermore, the resent iu- "ontion combines as one of the o ements of llt) the condenser, certain elements of the tube.

What is elanncd 1s: l. A iixed condenser comprising in combination with a tube, an electrical conductor adapted to embrace a portion of the tube,

and. a dielectric material interposed between the conductor and the tube.

2. A grid condenser comprising a conductor adapted to embrace a metallic portion of a tube, a dielectric material interposed between the conductor and the metallic poi'- tion of the tube, and means for establishing the grid of the tube, where-b said induced current will be led to tlic grid of the tube.

4. In combination with a radio tube, an electrical conductor adapted to surround the metallic base thereof, said conductor being .insulated with respect to said metallic base in such a manner as to permit of a current in the metallic base and induced from said conductor, and means for leading said induced current into the grid circuit of the tube.

5. A vacuum tube having a base, a receiving means for the base, a condenser, a portion of said base forming one of the plates of said condenser.

6. A vacuum tube having a base, a. receiv- -ing means for the base, a condenser, said condenser surrounfrling one of the elements of the tube, which element forms one ol the plates of the condenser.

ROBERT C. PITARD. 

